Pressure assist for roller platen data recorder

ABSTRACT

A roller platen data recorder having a pivoted openable head, a pivoted platen drive lever handle opposite the head pivot, with a spring to resist handle movement, the improvement of a wedge link serving as an anchor for the spring in place of the conventional machine frame anchor, the wedge link positioned to exert an ever greater moment in the direction of applied platen pressure as the handle is forced to pivot and the platen advances.

n I [in United States Patent 191 [111 3,802,341 Valentine 1 Apr. 9, 1974 [54] PRESSURE ASSIST FOR ROLLER PLATE 2,664,819 1/1954 Janke 101/274 DATA RECORDER 2,746,388 5/1956 Gruver et al 101/269 X 3,221,653 12/1965 Bell et al [01/269 [75] Inventor: Richard E. Valentine, Mentor, Ohio [73] Assignee: Addressograph-Multigraph Examinerkobeft Pulfrey Corporation, Cleveland Assistant Examiner-Edward Coven 1 Attorney, Agent, or Firm-Ray S. Pyle [22] F1led: Dec. 18, 1972 [21] Appl. No.2 316,318 [57] ABSTRACT A roller platen data recorder having a pivoted open- [52] US. Cl. .f. 101/269 able head, a pivoted platen drive level handle pp [51] Int. Cl B411 3/06 the head Pivot, with a Spring to resist handle 58 Field of Search 101 /269-274, ment, the improvement of a Wedge link serving as an 101 /45 2 7 297 2 anchor for the spring in place of the conventional machine frame anchor, the wedge link positioned to exert 56 References Cited an ever greater moment in the. direction of applied UNITED STATES PATENTS platen pressure as the handle is forced to pivot and the platen advances. 3,447,458 6/1969 Hu 101/269 2,692,555 lO/1954 Gruver lOl/274 X 3 Claims, 10 Drawing Figures v 3 37 I/ -35 w Z6 1 1 /6 x f ,6 e 1 4/ 39 we? of i 1 r PRESSURE ASSIST FOR ROLLER PLATEN DATA RECORDER Y BACKGROUND OF THE INVENTION A data recorder which has a superstructure pivoted atthe back of a base, with a pivoted handle on the front of the superstructure, is referred to colloquially as a pump handle recorder.

This type of recorder is old and well known. FIG. 1

' alone; and,

of the drawing illustrates the essential working parts of such a recorder. The handle load F is a direct result of a spring load P where the bearings for the platen are slides carried in slots in two side plates. The handle is pivoted to the base, a driver arm for the platen is connected to receive drive force from the handle, and a preloaded spring connected to the driver arm and the frame for the side plates provides resistance which necessitates handle pressure, thus producing platen pressure.

Unfortunately, the platen pressure is proportional to the ratio of the pivot arm R (the center about the handle load) to the pivot arm X, (the increasing distance from the center of the platen to the same pivot point for R multiplied by the force applied: P=R X,. X F This is a fact well documented by use of the prior devices. A very strong spring, requiring 30 to 35 pounds of force for F is required to produce a good print at the end of the platen stroke.

US. Pat. Nos. 2,664,819 and 2,692,555 illustrate the prior concept. In each a spring is used. The spring serves the purpose of returning the platen and holding the handlein the park position. However, the springs are much stronger than needed for such purposes alone. The springs provide a resistance load to increase operator applied pressure.

SUMMARY OF THE INVENTION The invention resides in the utilization of the load producing spring to press a wedge, preferably an articulate'd two-part link, between the machine base and the pivoted superstructure upon pressure points which are located to induce a moment in the direction of platen load. The object is to use a very light spring for ease of operation, and to employ the increasing spring load as the handle is activated as a dynamic wedge force, rather than to anchor the spring to a static machine part.

IN THE DRAWINGS FIG. 1 is a perspective view, in an open position, of a data recorder embodying the principles of this invention.

FIG. 2 is the machine in a closed position prior to handle activation.

FIG. 3 is a top plan of the machine .with its decorative cover removed.

FIG. 4 is a vertical section taken along line 4-4 of FIG. 2.

FIG. 5 is the section of FIG. 4 with the platen actuated to the end of its print stroke.

FIG. 6 is a detail of the platen support as viewed along line 6-6 of FIG. 4.

FIG. 7 is a force vector analysis illustration of the drive linkage of this invention.

FIG. 8 is a schematic representation of a prior art device.

FIG. 9 is a table of applied force from wedge action FIG. 10 is a chart of loads from two sources and the resultant applied platen load.

DESCRIPTION OF THE PREFERRED EMBODIMENT The prior art structure has been shown in FIG. 8 and described briefly in the background description because the understanding of the invention will be much greater by comparing what appears to be a simple change from the prior art, but which produces an amazing difference in result. Although similar in appearance to the prior art, the construction, operation, and result of the illustrated embodiment of the invention is amazingly new and beneficial.

This new and improved data recorder comprises a base 10 with a pivoted head, which is referred to hereinafter as a superstructure. This term is believed to be more accurate in its descriptive characteristics.

The superstructure is built basically around two side plates 16 each of which has a longitudinal slot 18, which serves as a bearing race. This superstructure is pivoted upon the base about a crossbar pivot rod 19. A bearing 20 rides in each bearing race 18. A platen shaft 22 is carried by the two bearings 20 and supports an independently rotatable platen 23.

The superstructure 14 may be said to swing between a first position resting upon the base, as shown in FIG. 2, to a second position raised above said base, as shown in FIG. 1. Thus, the two slots 18, which jointly define a bearing race for the bearings 20, may be said to define a path. The platen will operatein that path from a home position shown in FIG. 4, across the work area of the bed 11, and return to the home position.

Drive arms 25 are attached at one end to shaft 22 to drive the platen 23, (at one end) and captured by a vertically shiftable axis defined by bearings 26 and shaft 28 operating in two race slots 27 in a side plate 16. Shaft 28 extends between the bearings 26. There are two of the drive arms 25 in the preferred embodiment shown.

A handle 30 is provided for manual operation of the data recorder. The operator places embossed printing members on the bed 11, together with whatever forms are to be used. If the machine is to be a ribbon head machine, a ribbon carrier is capable of being built into the head. More often, self-contained form sets are employed which do not require an ink ribbon. Then, the operator closes the head superstructure to the position shown in FIG.'2, and presses downwardly on the handle 30. It is at this moment that the operator will notice the extraordinary differences between the prior art devices and the present invention. The prior art devices will require 30 to 35 pounds of pressure to produce a satisfactory print, whereas this invention will require about half that pressure and yet produce a more uniform and satisfactory print along the entire length.

This phenomina of results is obtained by means of utilization of the force of a spring. In the prior art, the

spring is used only to return the handle and platen to its home position, and to require the operator to place a heavy operating load downwardly to force the platen against the forms being printed. In this invention a lever wedge 33 is employed to produce a very large wedge force in proportion to an applied load tending to straighten the bow. A one-piece spring steel band is feasible, but a two-piece structure is easier to produce and operate. Hence, in the preferred form, two links 34 and 35 are connected as articulated levers. The levers are connected at one end to the base by a pivot 36, and are connected to the superstructure side plates by a rod 37 extending between the side plates. The rod 37 is located at a position above the base and advanced in the direction of the path of the platen. The preferred position is somewhat above the actual pair of bearing race slots 18.

The articulated levers 33 have an angulation approaching very close to a straight line 180 angle. The very slight angulation, which is not exact in its requirements, produces an extremely great resultant force on the pivot points 36 and 37, for a relatively slight force on the apex directed to the direction which would urge the articulated lever to a 180 condition.

Note that the pivot 36 is located on the side of pivot 19 opposite the location of the printing bed. If the pivot were located over pivot 19 or 33 forward thereof, a force directed against the apex of the lever 33 would act as a lifting device and open the head.

An attachment bar 38 carried by the drive arm 25, and a hook 39 on the link 34 provide attachment points for a spring 40. Bar 38 also provides a connection for a coupling arm 39 connecting lever 30 to arms 25. Spring 40 is preloaded even in the relaxed condition shown in FIG. 4, and as the handle 30 is depressed for the purpose of printing, the spring is extended and the force accentuated. In this way, as the platen advances across the bed in the printing operation, the force of the handle 30, which originally produced a considerable downward force through its pivot 41, gradually diminishes as the handle pivots. However, a moment is created which acts to press the superstructure to the base with an ever increasing force through the action of the spring 40 on lever wedge 33. Calculations can be made to establish the degree of such useful reaction.

Refer to FIG. 7, and use the following table together with the obvious distance symbols on the FIG. 7, not included in the table.

P Spring Load Pp Platen Resultant Load F Perpendicular Load P Toggle Load M Toggle Moment Load The following equations yield the load that is created at the platen position as the handle is pulled down.

2. F/P l,/1 F=l,/1 P AND P =R II P 3. M P X X AND 4. M1 P1 X RT Then, considering that the distance R 1, will remain a relatively constant ratio and establishing a machine in which that is a constant, K, of 3.5, then Pp is equal to R /X KP and the table of FIG. 9 will indicate a test verified calculation for a movement of the platen through 8 positions from beginning to end of the stroke.

The calculations of FIG. 9 are for the load produced solely through the action of the spring 40, and does not account for that portion of the load upon the platen which is applied by the operator applied load upon the handle 30.

It is normal in the prior art that the load at the platen position will decrease as the handle is rotated in the printing action. The same decrease is true in this improved device, and were it not for the present invention, would be exactly like the prior art. In the FIG. 10, a full line 45 in the upper corner of the chart illustrates the total platen load of handle pressure plus calculated toggle pressure as achieved by this invention. At the bottom of the chart, the toggle platen load as calculated is diagramed as line 46. Then, a broken line 47 between the two full line graph line indicates the force of the platen in prior at practice and the drastic fall-off of platen pressure in a device of this nature without the use of the articulated lever assist. Note that the pressure load drops considerably below that which is considered to be sufficient for a satisfactory printout of pressure release forms. The line 45, therefore, represents the present invention results. This chart cannot properly represent the great operator advantage of greatly reduced manual pressure required to achieve the useful line 45 results.

The calculations indicated have been borne out in actual operation and therefore have been fully confirmed.

What is claimed is:

1. In a data recorder having a base and a superstructure pivotally mounted on said base by a pivot, and said superstructure extending over said base, the superstructure having a roller platen and a lever handle for driving said platen in a path from a home position over said base in a first direction to a terminus and return in the opposite direction to said home position, the improvement in a means to increase applied force from said lever handle to the platen in comparison to the drive force applied to said handle, comprising;

a lever wedge means having a generally angulated configuration with an apex, said lever wedge means having a first end attached to said base on the side of said pivot opposite said platen path and extending upwardly from the base and laterally to a position terminating in an attachment to said superstructure at a position over said path; drive means including said handle for said platen, said handle being pivotally carried by a pivotal mount on said superstructure and having a yieldable tie member extending from the apex of said lever wedge means to said drive means, said tie member attached to said platen drive means by an attachment means located at a position removed from the pivotal mount of said handle, said attachment means located to swing away from the lever wedge means as the handle is pivoted in the platen drive act, whereby driving said platen by pivoting said handle causes an increasing pressure to the apex of said lever wedge means in a direction tending to straighten said lever wedge means, thereby forcing the roller platen against said base.

2. The improvement according to claim 1, further characterized by said lever wedge means being con- 0 structed of two links articulated by a pivot joint, and

the links having an angular relationship with said pivot joint constituting said apex.

3. The improvement according to claim 1, further characterized by said superstructure having a longitudinal guide race to direct the platen excursion;

said platen carried by a bearing means mounted in said guide race;

drive arm which is translated into drive force of said platen; and said tie member is a spring connected between said coupling link and lever wedge means. 

1. In a data recorder having a base and a superstructure pivotally mounted on said base by a pivot, and said superstructure extending over said base, the superstructure having a roller platen and a lever handle for driving said platen in a path from a home position over said base in a first direction to a terminus and return in the opposite direction to said home position, the improvement in a means to increase applied force from said lever handle to the platen in comparison to the drive force applied to said handle, comprising; a lever wedge means having a generally angulated configuration with an apex, said lever wedge means having a first end attached to said base on the side of said pivot opposite said platen path and extending upwardly from the base and laterally to a position terminating in an attachment to said superstructure at a position over said path; a drive means including said handle for said platen, said handle being pivotally carried by a pivotal mount on said superstructure and having a yieldable tie member extending from the apex of said lever wedge means to said drive means, said tie member attached to said platen drive means by an attachment means located at a position removed from the pivotal mount of said handle, said attachment means located to swing away from the lever wedge means as the handle is pivoted in the platen drive act, whereby driving said platen by pivoting said handle causes an increasing pressure to the apex of said lever wedge means in a direction tending to straighten said lever wedge means, thereby forcing the roller platen against said base.
 2. The improvement according to claim 1, further characterized by said lever wedge means being constructed of two links articulated by a pivot joint, and the links having an angular relationship with said pivot joint constituting said apex.
 3. The improvement according to claim 1, further characterized by said superstructure having a longitudinal guide race to direct the platen excursion; said platen carried by a bearing means mounted in said guide race; said drive means including a drive arm connected at one end to said bearing means and captured in a second guide race at the other end; a coupling link connecting said handle to said drive arm, the connection being located such that rotation of the handle will produce a draw force on said drive arm which is translated into drive force of said platen; and said tie member is a spring connected between said coupling link and lever wedge means. 